Took me a while to learn this stuff as I reinstalled ME2 after a few years of not playing it. This is just a guide to wear Morinth armor (with kestrel armor effects), the only npc armor that I am aware of which has no clipping issue with femshep. I am sharing this also as a reminder to myself in case I reinstalled the game and want to mod it again.

Open (with Notepad++) Coalisced.ini in the directory Mass Effect 2\BioGame\Config\PC\Cooked (but at first make reserve copy of this file).

Find (hotkey Ctrl+F) 
(1) go to [SFXGame.SFXPawn_Player] and write under it in section "CasualAppearances":

CasualAppearances=(Id=99,Type=CustomizableType_Torso,Mesh=(Male="BIOG_HMF_ARM_LGT_R.LGTc.HMF_ARM_LGTc_MDL",Female="BIOG_HMF_ARM_LGT_R.LGTc.HMF_ARM_LGTc_MDL"),PlotFlag=-1)

TorsoAppearances=(Id=99,Type=CustomizableType_Torso,Mesh=(Male="BIOG_HMF_ARM_LGT_R.LGTc.HMF_ARM_LGTc_MDL",Female="BIOG_HMF_ARM_LGT_R.LGTc.HMF_ARM_LGTc_MDL"),GameEffects=("SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_TorsoMeleeBonus","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_TorsoShieldBo
nus","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_TorsoWeaponDmgBonus"),PlotFlag=-1)

ShoulderAppearances=(Id=99,Type=CustomizableType_Shoulders,GameEffects=("SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_ShoulderMeleeBonus","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_ShoulderSh
ieldBonus"),PlotFlag=-1)

ArmAppearances=(Id=99,Type=CustomizableType_Arms,GameEffects=("SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_ArmMeleeBonus","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_ArmShieldBonus
","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_ArmWeaponDmgBonus"),PlotFlag=-1)

LegAppearances=(Id=99,Type=CustomizableType_Legs,GameEffects=("SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_LegHvyAmmoBonus","SFXGameContentDLC_CER_02.SFXGameEffect_Gear_CER02_LegShieldBo
nus"),PlotFlag=-1)

(2) find [SFXGame.SFXGameModeBase]
and write under it this line:
Bindings=( Name="F12", Command="StreamLevelIn BioD_Nor_231Morinth | StreamLevelIn BioD_Nor_000Cabin | OnTap 2.0 showmenu | OnTap 3.0 OpenGUI
Personalization" )

or 

(3) An alternative and more stable method instead of (2) above is as follows (as advised by VioletteHeaven in the comment section)

Find [Engine.PackagesToAlwaysCook]
and write:
SeekFreePackage=BioD_Nor_231Morinth

Find [Engine.StartupPackages] 
and write:
DLCStartupPackage=BioD_Nor_231Morinth


Save file's changes and close program.

THEN download ME2IniFixer by Techpriest1 
link
and use it (right in directory with Coalisced.ini)

Done! 
Now press F12 and you can change your armor accordingly.

Other nice links with regards to Morinth's armor: http://social.bioware.com/project/7960/

Credits:
VioletteHeaven - Learned about editing Coalisced.ini from his post "Techno Rose- Miranda's armor"
RangerDulann - Learned about Morinth's Armor ID Codes from his file "Play as Morinth"
Learned about casual appearance modding - Morinth's armor from this post
http://masseffectmods.tumblr.com/page/2